This competitive revision proposes to extend our parent award, Development of a Translational Tool to Study Yoga Therapy (1R01AT006466-01) by incorporating a substantial focus on US active-duty military and veterans, populations who may greatly benefit from yoga interventions. The parent study is developing a tool to assess the components of yoga (Essential Properties of Yoga Questionnaire; EPYQ), which will allow researchers to better examine the efficacy of yoga therapy. The first two phases of the parent study, which developed and refined items, have been completed, and we now have a prototype instrument. Phase III will involve a large-scale administration of the prototype to refine it throuh factor analysis and item-response theory. Aim 1 of the competitive revision is to represent veterans and active duty military by including a large sample of active-duty military and veterans in Phase III. Phase IV will establish the psychometric properties of the EPYQ (i.e., reliability an validity) to produce a final questionnaire; Aim 2 of the competitive revision is to expand Phase IV to include classes with military and active-duty veterans to examine the psychometric properties of the EPYQ in these groups. In Aim 3, we will conduct qualitative interviews with researchers/ teachers who teach or conduct research on yoga interventions with active-duty and veteran military personnel and with yoga students who are active-duty military or veterans. Through these interviews, we will examine perceptions of acceptability and effectiveness of different components of yoga for different physical and mental health conditions. These findings will also inform the model of mechanisms of effect of yoga interventions being developed in the parent study. As an exploratory aim, we will develop a database of interventions that have been conducted in active-duty military and veteran samples, asking researchers to complete the EPYQ with regard to their interventions, and including those codes along with study findings (e.g., effect sizes on different outcome measures). We will conduct preliminary analyses linking EPYQ ratings to existing de- identified health outcome data. This aim, while preliminary, is essential in linking specific components of yoga interventions with efficacy for specific problems in military and veteran groups. Finally, this project will help us to establish collaborative ties hat allow us to develop yoga research in veteran and military populations, which will lead to wider use of the EPYQ in yoga research studies in veteran and active-duty military populations, the ability to link the active components of yoga to various outcomes in these populations, and the development of future research initiatives and proposals. Including adequate representation of veteran and active-duty military in the development of the EPYQ will allow future research on yoga interventions with these groups to determine the effects of various dimensions of yoga on well-being and to design more effective and better- targeted interventions.